Poster Abstracts

Name/Affiliation:  Lynne Hillenbrand (caltech)

Title:  EMPIRICAL LIMITS ON RADIAL VELOCITY PLANET DETECTION FOR STARS YOUNGER THAN THE SUN

Abstract:
We report initial results from our long term program measuring precision radial velocities and chromospheric activity levels for stars younger than the Sun. Using a sample of roughly 170 stars, we establish an empirical relationship between chromospheric activity, parameterized by R'HK, and radial velocity ``jitter", or rms in the observed radial velocities. The jitter floor, which increases with increasing stellar activity, limits the minimum mass companion that is detectable around young stars using the radial velocity technique to values significantly higher than those corresponding to the instrumental limit. Adopting a median activity-age relationship and assuming a solar-mass primary, we can derive the astrophysical limits to planet detection as a function of stellar age in a typical monitoring program thathas several tens of observations. For stars younger than 100 / 300 / 1000 Myr, the stochastic jitter component restricts detectable companion masses to greater than 0.3 / 0.2 / 0.1 M_Jupiter at the mean jitter-activity levels.